The invention relates to a process for the purification of waste gases containing hydrochloric acid and sulphur dioxide derived from incinerating plant, in particular refuse incinerating plant such as incineration plant for domestic refuse and special refuse, with the use of a scrubbing agent which can be regenerated.
Processes are known for the treatment of combustion waste gases containing SO.sub.2 and HCl and have been described for example in the laid-open specification DE-OS 34 33 759, DE-OS 34 08 705, DE-OS 27 32 580 and DE OS 33 05 120. However, in all those processes the HCl washed out of the waste gas must be disposed of in the form of metal chlorides whereby the problem of air pollution is shifted to a waste water problem.
An object of the invention is a provision of a process for purifying the waste gases from incineration plant of the aforesaid type in which hydrochloric acid and gypsum can be recovered, the addition of scrubbing agent being reduced to a minimum. In particular it is intended that the HCl content of the waste gases need not be disposed of in the form of metal chloride, but can be sold as a commercial product of high value.